Celsius to Kelvin - Overview, Formula, Features, FAQs

Absolute Zero

Absolute Zero is the lowest theoretical temperature that can exist in the universe. It is defined as 0 Kelvin (0 K), which is equal to –273.15 °C on the Celsius scale. At this temperature, a system possesses minimum possible thermal energy.

The concept of absolute zero arises from the behavior of gases. According to Charles’ Law, the volume of a gas decreases uniformly with a decrease in temperature. If a gas were cooled further, its volume would theoretically become zero at –273.15 °C. This temperature was extrapolated and defined as absolute zero.

Kelvin Scale and Absolute Zero

The Kelvin scale is an absolute temperature scale that starts from absolute zero.

• Absolute zero = 0 K
• Freezing point of water = 273.15 K
• Boiling point of water = 373.15 K

Unlike Celsius, Kelvin has no negative values, making it suitable for scientific calculations.

Also read :

Temperature Conversions

The following is a list of conversion formulas

• Celsius into Kelvin, K = ${ }^0 \mathrm{C}$ + 273.15
• Celsius into Fahrenheit, F = (9/5) ⁰C + 32
• Fahrenheit to Celsius, ${ }^0 \mathrm{C}$ = (5/9) (F-32)
• Fahrenheit to Kelvin, K = (5/9) (F + 459.67)
• Fahrenheit to Rankin, R = F + 459.67
• Positions in Kelvin, K = (5/9) R
• Freezing point of water=273.15K=0${ }^0 \mathrm{C}$=32⁰F
• Boiling point of water=373.15K=100${ }^0 \mathrm{C}$=212⁰F

Some Solved Examples

Example 1: Convert 25°C to Kelvin.

Solution:

As we know,

K = °C+273.15K

K= 25+273.15 = 298.15 K

Hence, the temperature in Kelvin is 298.15 K.

Example 2: What is the freezing point of water in Kelvin?

Solution:

As we know, the freezing point of water is 0°C.

Using formula, K = °C+273.15K

K = 0+273.15 = 273.15 K

Hence, the freezing point of water is 273.15 K.

Example 3: Convert the boiling point of water, 100°C, to Kelvin.

Solution:

As we know,

K = °C+273.15 K

K = 100+273.15 = 373.15 K

Hence, the boiling point of water is 373.15 K.

Example 4: The surface temperature on Pluto can drop to -230°C. Convert this to Kelvin.

Solution:

As we know,

K = °C + 273.15 K

K= −230 + 273.15 = 43.15 K

Hence, the temperature in Kelvin is 43.15  K.

Example 5: Which of the following temperatures is the lowest?

A) –40°C
B) 233 K
C) –10°C
D) 250 K

Solution:

Convert all to Kelvin:

• $-40^{\circ} \mathrm{C}=233 \mathrm{~K}$
• $-10^{\circ} \mathrm{C}=263 \mathrm{~K}$
• $250 \mathrm{~K}=250 \mathrm{~K}$

Lowest $=233 \mathrm{~K}$

Hence, the correct answer is option (B)